This observational study examined changes in teachers' instruction and student outcomes in response to a 3-year-long professional development collaboration between university researchers and a middle-school language arts team. Professional development supported teachers in implementing multimedia anchored instruction, a video-based instructional method shown to be effective for diverse learners. The Integrated Curriculum Project (ICP-3) used multimedia anchored instruction to promote constructivist reform and infuse technology into an integrated social studies and language arts curriculum to improve literacy and critical thinking skills for at-risk adolescents, including students with disabilities and those from culturally and linguistically diverse backgrounds. Findings revealed that teachers moved toward a more learner-centered instructional approach and that both teachers and students made significant changes in classroom behaviors, including the quantity and quality of questions and time spent in small-group discussion. Implications for research and practice regarding sustained, collaborative professional development in technology integration, in this case, using multimedia anchored instruction, are presented. (Contains 2 tables and 4 figures.)